DRAFT UGANDA STANDARD  
  DUS 2373 -2 
First  Edition  
yyyy -mm-dd 
 
 
 Reference number  
DUS 2373 -2: 202 2 
© UNBS 202 2 
  
Mosquito repellents — Performance test guidelines — Part 2: 
Spatial repellents  
 DUS 2373 -2: 2022 
ii © UNB S 2022 – All rights reserved  
 Compliance with this standard does not, of itself confer immunity from legal obligations  
A Uganda Standard does not purport to include all necessary provisions of a contract.  Users are 
responsible for its correct application  
© UNBS 2022. 
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilised in any 
form or by any means, electronic or mechanical, including photocopying and mic rofilm, without prior written 
permission from UNBS.  
Requests for permission to reproduce this document should be addressed to  
The Executive Director  
Uganda National Bureau of Standards  
P.O. Box 6329  
Kampala  
Uganda  
Tel: +256 41 4 333 2 50/1/2/3  
Fax: +256 41 4 286 123  
E-mail: info@unbs.go.ug  
Web: www.unbs.go.ug  DUS 2373 -2:2022 
© UNBS 202 2 – All rights reserved  iii 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ............................  iv 
1 Scope.  ................................ ................................ ................................ ................................ .....................  1 
2 Normative references.  ................................ ................................ ................................ ...........................  1 
3 Terms and definitions.  ................................ ................................ ................................ ..........................  1 
4  Laboratory studies  ................................ ................................ ................................ ................................  2 
4.1  Objective  ................................ ................................ ................................ ................................ ................  2 
4.2  Mosquito rearing and physiological status.  ................................ ................................ ......................  4 
4.3 Laboratory test procedure  ................................ ................................ ................................ ....................  4 
5 Spatial repellency of active ingredients (technical material)  ................................ ............................  4 
5.1 Movement away from a chemical stimulus  ................................ ................................ ........................  4 
5.2  Host attraction -inhibition  ................................ ................................ ................................ .....................  6 
5.3  Spatial repellency of active ingredien ts against insecticide -resistant strains  ..............................  8 
5.4  Protective efficacy of formulated products  ................................ ................................ ........................  8 
6  Semi -field trials of formulated prod ucts ................................ ................................ ...........................  10 
6.1  General  ................................ ................................ ................................ ................................ .................  10 
6.2  Study design  ................................ ................................ ................................ ................................ ....... 10 
6.3  Indoor effective dos age and duration of protective efficacy  ................................ ..........................  11 
6.4  Outdoor effective dosage and duration of protective efficacy  ................................ ......................  12 
7  Field trials of f ormulated products  ................................ ................................ ................................ .... 12 
8  Ethical considerations  ................................ ................................ ................................ ........................  13 
8.1  General  ................................ ................................ ................................ ................................ ................  13 
8.2  Informed consent  ................................ ................................ ................................ ...............................  14 
8.3  Human landing catch in semi -field and field testing  ................................ ................................ ....... 14 
Annex A  (Informative)   Definition of knockdown a nd mortality for adult mosquitoes  ...........................  15 
Annex B  (Informative)   Example of informed consent form  ................................ ................................ ...... 16 
B.1 Informed consent form for part icipants in human landing catches for: (name the group of 
individuals for whom this consent is written)  ................................ ................................ ..................  16 
B.2 Part I: Information sheet  ................................ ................................ ................................ .....................  16 
B.2.1  Introduction  ................................ ................................ ................................ ................................ ..........  16 
B.2.2  Purpose of the research  ................................ ................................ ................................ .....................  17 
B.2.3  Type of research intervention and procedures  ................................ ................................ ................  17 
B.2.4  Voluntary participation  ................................ ................................ ................................ .......................  17 
B.2.5  Risks  ................................ ................................ ................................ ................................ .....................  18 
B.2.6  Right to refuse or withdraw  ................................ ................................ ................................ ................  18 
B.2.7  Who to contact  ................................ ................................ ................................ ................................ ..... 19 
B.3 Part II: Certificate of consent  ................................ ................................ ................................ .............  19 
B.3.1  Example  ................................ ................................ ................................ ................................ ................  19 
B.3.2  Statement by the researcher or other person taking consent: ................................ .......................  20 
Bibliography  ................................ ................................ ................................ ................................ ......................  21 
  
 DUS 2373 -2: 2022 
iv © UNB S 2022 – All rights reserved  
 Foreword  
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry of Trade , Industry and 
Cooperatives established under Cap 327 , of the Laws of Uganda , as amended .  UNBS is mandated to co -
ordinate the elaboration of standards and is  
(a) a me mber of International Organisation for Standardisation (ISO) and  
(b) a contact point for the WHO/FAO Codex Alimentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT  Agreement  of the World Trade Organisation (WTO).  
The work of preparing  Uganda Standards is carried out through Technical Committees. A Technical 
Committee is established to deliberate on standards in a given field or area and consists of key stakeholders 
including government, academia, consumer groups, private sector and oth er interested parties.  
Draft Uganda Standards adopted by the Technical Committee are widely circulated to stakeholders and the 
general public for comments. The committee reviews the comments before recommending the draft standards 
for approval and declara tion as Uganda Standards by the National Standards Council.  
The committee responsible for this document is Technical Committee UNBS /TC 301- Chemis try. 
  
DUS 2373  consists of the following parts, under the general title Mosquito repellents  — Performance te sts 
guidelines:  
 Part 1: Skin applied repellents.  
  Part 2: Spatial repellents.  
  DUS 2373 -2:2022 
© UNBS 202 2 – All rights reserved  v 
  Introduction  
The term ‘spatial repellency  is used here to refer to a range of insect behaviors induced by airborne chemicals 
that result in a reduction in human –vector con tact and therefore personal protection. The behaviors can 
include movement away from a chemical stimulus, interference with host detection (attraction/inhibition) and 
feeding response.  
While many household insecticide products have been used for personal p rotection, most are based on the 
insecticidal activity (knock -down and mortality) of the active ingredient.  
The document provides guidance and describes steps for laboratory testing and for semi -field and field 
evaluations of spatial repellent products (te chnical materials and formulated products) designed to provide 
protection in a specific space (indoor and/or outdoor) against mosquitoes. With some modifications, the 
guidelines can be used to determine the efficacy and personal protectiveness of candidate  products against 
other flying nuisance pests. These guidelines may have to be modified when proof of principle is established 
(i.e. the public health value of spatial repellents for vector -borne disease control) and as new methods for 
assessing the spatia l repellency of such products become available.  
These guidelines are designed for using active ingredients that have already undergone safety assessment, 
including toxicity by inhalation. Nevertheless, any adverse -effects or undesirable characteristics obs erved 
during laboratory studies and field trials should be recorded and reported.  
Technical material or formulated products submitted for laboratory testing and field trials should be sent with 
the material safety data sheet, the labeling recommendations a nd the manufacturer’s certification that the 
product is within the company’s manufacturing specifications. Independent physical and chemical assessment 
for compliance with the specifications may be required before efficacy testing.  
Biological tests are sub ject to the variations inherent to living organisms. Test insects must be reared carefully 
for standardized size and good biological fitness in order to ensure representative responses to test 
compounds. Testing should be conducted under the close supervis ion of personnel familiar with biological 
testing of insecticides and by sound scientific and experimental procedures; the principles of good laboratory 
practice or other suitable quality assurance schemes should be applied.  
All laboratory and field person nel should be given adequate training in safety and the standard operating 
procedures associated with an assay before beginning testing, and such training should be documented. Use 
of a standard operating procedure for data processing, management and valid ation is advisable, and copies of 
the procedures should be made available and accessible in the relevant languages for all study staff.  
The quality of data reporting should be sufficient to allow comparisons of efficacy at multiple evaluation sites. 
The mi nimum data to be reported include a measure of centrality (e.g. mean), sample size and a measure of 
variability (e.g. standard error).  
Evaluations of spatial repellents should be conducted in accordance with applicable national ethical 
regulations.  
 DRAFT UGANDA STANDARD  DUS 2373 -2:2022 
 
© UNBS 2022 – All rights reserved  1 
 Mosqu ito repellents — Performance test guidelines — Part 2: 
Spatial repellents  
1 Scope . 
This Draft Uganda Standard provides guidelines  for the design and execution of studies to evaluate the 
performance of mosquito repellents formulated and prepared for space a pplication.  
2 Normative references . 
There are no normative ref erences in this document.  
3 Terms and definitions . 
For the purposes of this standard, the following terms and definitions apply.  
ISO and IEC maintain terminological databases for use in standard ization at the following addresses:  
— ISO Online browsing platform: available at http://www.iso.org/obp   
3.1  
spatial repellent  
chemical products designed to be 'active' (requiring heat or electricity) or 'passive' (requiring no heat or 
electricity) and release volatile chemicals into the air within the treated space . 
 
3.2 
landing  
act of flying on to or approaching and settling on human skin without probing or biting  
3.3  
probe  
act of penetrating human skin by mosquito  mouthparts without ingestion of blood  
3.4  
bite  
act of penetrating human skin by mosquito mouthparts with ingestion of blood, typically associated with 
abdominal swelling and colour change  
3.5  
crossing  
act of passage by mosquitoes from an area of untreated skin to an area of treated skin. A crossing may be 
quantified either or both by the distance the mosquitoes moves onto treated skin or by how long the 
mosquitoes remains on the treated skin  
3.6  
unconfirmed event  
landing, probe, bite, or crossi ng not followed by another similar event within 30 min   
2 © UNBS 202 2 – All rights  reserved  
 3.7  
confirming event  
one landing, probe, bite, or crossing followed by another similar event within 30 minutes. The first event is 
confirmed by the second; the second event in the confirming event  
3.8  
human subject  
living individual about whom an investigator conducting research obtains either data through intervention or 
interaction with the individual or identifiable private information  
3.9  
questing  
behaviour  of mosquitoes actively seeking a host  
3.10  
repellent  
product that deters the host -seeking behaviour of mosquito, from approaching or settling on treated human 
skin 
3.11  
Complete Protection Time (CPT)  
time from application of repellent until efficacy failure as it is defined in each s tudy – for example, the time 
from application until the first efficacy failure event confirmed within 30 minutes by a second similar event.  
3.12  
dose determination  
testing procedure used to estimate a “typical consumer dose” of a topical repellent  
3.13  
Vector -borne diseases  
infections transmitted by the bite of infected arthropod species, such as mosquitoes, ticks, triatomine bugs, 
sandflies, and blackflies  
3.14 
dose –response relations  
measurement of the relationship between the quantity of a substan ce or exposure to radiation (the dose) and 
its overall effect (the response) on an organism.  
4  Laboratory studies  
4.1  General  
4.1.1  Objective   
4.1.1 .1 The primary objective of laboratory studies is to determine the inherent properties of the active 
ingredient  (AI) under well -controlled, standardized conditions and its activity against well -characterized 
mosquito strains .  
Such studies include measurement of movement away from a chemical stimulus, interference with host 
detection (attraction –inhibition) and feeding response. Laboratory studies also include determinations of the 
efficacy, including the duration of protection, of a formulated product in various delivery formats under well -
controlled, standard conditions.  
4.1.1.2 The specific objectives of l aboratory studies are to :  
a) establish dose –response relations and determine the effective dosage (ED) of the AI for 50% and 95% 
(ED 50 and ED 95) movement away from a chemical stimulus;  DUS  2373 -2:2022 
© UNBS 202 2 – All rights reserved  3 
 b) establish dose –response relations and determine the ED 50 and ED 95 of the AI for host attraction –
inhibition;  
c) determine the efficacy and duration of protection (landing and feeding inhibition) of formulated spatial 
repellent products.  
4.1.1.3  If the spatial repellent product is intended for application to a large surfac e area (e.g. fabric), 
determination of contact irritancy may also be required, following established guidelines.   
4.1.1.4  If there is any significant mortality in the spatial repellency assay (see below), the insecticidal 
activity (e.g. vapor toxicity) of  the product should be determined by established guidelines, to fully understand 
its overall performance.   
4.1.1.5  A flow -chart of the decision -making process for laboratory studies of a candidate spatial repellent 
product is shown in figure 1.  
 
Figure 1  – Flow chart for making decisions on the basis of laboratory studies of candidate spatial 
repellent technical material  
4.1.1.6  Ideally, tests should be conducted with three or more local anthropophilic, fully susceptible 
species of Anopheles (preferably An. gambiae S.L.) characterized according to standard guidelines for 
monitoring susceptibility.  
4.1.1.7 As the physiological status of mosquitoes can significantly affect their behavioral response, use of 
the assays described below for measuring various ph ysiological states (e.g. parity) should be considered.    
4 © UNBS 202 2 – All rights  reserved  
 4.1.2  Mosquito rearing and physiological status  
4.1.2.1  Use of standardized mosquito rearing and testing conditions for laboratory assays is essential to 
ensure the reliability and reproducibility o f data. The conditions are generally a temperature of 27 ± 2 °C, a 
relative humidity of 80 ± 10%, and a photoperiod of 12 h light: 12 h dark. Temperate species may have 
different requirements, and the assay conditions should be matched as closely as possib le to the 
environmental conditions of the target locale. Adults are maintained on sugar solution (typically 10% glucose 
on cotton wool or filter paper).  
4.1.2.2  Assays should be carried out on female mosquitoes that are nulliparous and of uniform age, 
preferably 5 –8 days post -emergence. Actively host -seeking females should be selected from general colony 
groups to ensure a maximum behavioral response. This can be done with an aspirator or an appropriate 
airflow apparatus while holding a hand close to (but not touching) the cage and collecting those mosquitoes 
that actively probe. Spatial repellency should be observed in female mosquitoes starved for the preceding 12 
h, preferably during times in the diel period that correspond to the biting activity of that  species. Mosquitoes 
must be transferred to holding containers or assay devices with care to avoid physically damaging them.  
4.1.3 Laboratory test procedure   
4.1.3.1  All test chambers and other assay instruments should be properly cleaned and decontaminat ed 
after the completion of each test according to assay -specific instructions. Test chambers must be checked for 
contamination by performing assays under blank conditions before the start of each subsequent test. Under 
chemical -free conditions, knock -down (see Annex A for a full definition of knock -down response) must not 
exceed 5% among mosquito populations held for 10 min.  
4.1.3.2  Inclusion of an appropriate, well -characterized active ingredient as a reference or positive control 
is highly recommended.  
4.1.3.3  The temperature and humidity at the time of testing as well as time of each replicate should be 
reported for each laboratory test.  
4.2  Spatial repellency of active ingredients (technical material)  
4.2.1 Movement away from a chemical stimulus  
4.2.1.1  The objective of this test is to measure the movement away from an active ingredient  in a spatial 
repellency assay, which is a modular test system (Figure 2).  
4.2.1.2  A central clear cylinder is connected to two metal test cylinders (one control (C) a nd one 
treatment (T)) with gated funnels to build one test unit (C –T). The funnel bevels (interior slope) are positioned 
towards the clear cylinder to facilitate mosquito movement into the metal cylinders of the test unit. A blank is 
placed within a metal spool at one end of the system and a treated substrate within another metal spool at the 
other end, creating a concentration gradient between the two ends. Pieces of opaque felt can be wrapped 
around the clear cylinder and over the rectangular ports in the  end caps to simulate darkness, depending on 
the diel pattern of the target species.  
4.2.1.3  As a negative control, substrate treated only with diluent is placed at both ends of the test unit (C –
C) simultaneously to ensure that no greater proportion of mo squitoes moves into a particular end of the test 
system for a given test population, time of day and assay conditions (i.e. temperature and humidity). If multiple 
assays are being run at the same time, the metal cylinders should be labeled C 1, C 2…C n and T 1, T2…T n to 
facilitate data recording.  
4.2.1.4  Serial dilutions of AI are made with acetone (or another suitable diluent recommended by the 
manufacturer) and tested to identify the effective dose range. Minimum of five concentrations covering a range 
of responses should be chosen, i.e. two to three concentrations resulting in <50% spatial repellent response 
and two to three concentrations that give >50% response (excluding 0% and 100% response).  DUS  2373 -2:2022 
© UNBS 202 2 – All rights reserved  5 
 
 
Figure 2 - Schematic drawing of the spatial repellency assay  
The spatial repellency assay components are: 1, end cap; 2, metallic net; 3, treated chamber; 4, linking 
section (with butterfly valve; 5, untreated chamber.  
4.2.1.5  Aliquots of 1.5 ml of the repellent AI and of the diluent are applied evenly to 11 x 25 cm (275 cm2) 
pieces of Whatman No. 1 paper with a pipette. All filter papers, both control (diluents only) and treatment (AI 
and diluent), are allowed to sit for 30 min (for acetone) or less (depending on the diluent) before the first test 
replicate is ini tiated, to ensure that the diluent has completely evaporated, leaving only the chemical of interest 
on the filter paper. Other substrates that can be used in the spatial repellency assay include polyester and 
cotton, depending on the textile or product for mat into which the AI is expected to be incorporated.  
4.2.1.6 The spatial repellency assay is typically performed under static airflow under a chemical hood. 
Groups of 20 female mosquitoes are introduced from holding tubes into the clear cylinder (with an aspirator) 
and are allowed to acclimatize to the test environment for 30 s. The number of mosquitoes that are physically 
damaged and are incapable of flying or walking is recorded to correct for the total mosquito sample size 
available to respond to the AI  in that replicate. The butterfly valves are simultaneously opened for 10 min to 
allow chemical vapors to flow through the test unit and also to allow free movement of the mosquitoes 
throughout the unit, as indicated by the grey arrows in Figure 2. The gat es are closed after 10 min, and the 
number of mosquitoes in each cylinder is recorded. The number of knock -down mosquitoes (see Annex 1) in 
each cylinder is also recorded. All mosquitoes are kept overnight to check for 24 -h mortality. If the mortality is 
significantly higher than among controls, insecticidal activity must be evaluated by established WHO efficacy 
guidelines  (Figure 1).  
4.2.1.7 Between replicates, the metal cylinders are disconnected from the clear cylinder and the end cap 
is removed from the  control metal cylinder for 3 min to allow passive ventilation of the AI from the clear and 
control metal cylinders before the next replicate. During the ventilation period, all treated substrates remain in 
place within the metal cylinders under the chemic al hood. Successive replicates are carried out without delay.  
4.2.1.8 The cylinders are washed at the end of each evaluation. The metal spools are washed with 
acetone solution. The clear cylinders, end caps, gated funnels and metal cylinders are washed wit h non -
fragrant laboratory detergent solution. Component sections are allowed to dry overnight before reuse for 
testing other AIs and/or dosages.  
4.2.1.9 Nine rep licates are performed for each active ingredient  dosage. At the conclusion of testing, the 
proportion of mosquitoes repelled by the treatment is determined. Spatial repellency is expressed as the  
6 © UNBS 202 2 – All rights  reserved  
 proportion of mosquitoes prevented from entering the treatment space in relation to all mosquitoes moving 
within the system and is calculated from a “spati al activity index”:  
 
Where,  
SAI  is the spatial activity index,  
Nc  is the number of mosquitoes in the control metal chamber,  
Nt  is the number of mosquitoes in the treatment metal chamber,  
Nm  is the total number of mosquitoes in the two metal chamber, a nd 
N  is the total number of mosquitoes in the test unit.  
4.2.1.10 The spatial activity index varies from –1 to 1:;zero indicates no response; –1 indicates that all 
mosquitoes moved into the treatment chamber, resulting in an attractant response; and 1 ind icates that all the 
mosquitoes moved into the control chamber (away from the treatment source), resulting in a spatial repellent 
response. If no movement is recorded within the system (i.e. Nt = 0, Nc = 0), the test is valid but the spatial 
activity index is 0. 
4.2.1.11 The spatial activity index is calculated for each replicat e, and the mean index for each active 
ingredient  dosage is analysed by probit -plane regression analysis, from which the ED 50 and ED 95 and 
corresponding 95% confidence limits can be es timated. The number of replicates, the total number of 
mosquitoes and the mean spatial activity index (± standard error) for each active ingredient dosage and 
negative control should be reported.  
4.2.2  Host attraction -inhibition  
4.2.2.1  The objective of this test is to measure the ability of an active ingredient  to inhibit mosquito 
attraction to a host. This is achieved by use of a Y -tube olfactometer to measure attraction to host odours in 
the absence and presence of the active ingredient . A dual port de sign, such as a Y -tube, is recommended, 
and a variety of suitable olfactometers can be used.  
4.2.2.2  A scheme of a Y -tube olfactometer is presented in Figure 3.  
4.2.2.3  A central base leg made of acrylic plastic constitutes the main body of the olfactome ter. Two 
branches meet the base leg at a decision point. Each branch has a trapping port with a mesh screen over the 
end, and each trapping port has a rotating circular door that also has a mesh screen. The mesh on the control 
and treatment trapping ports allows odours from the air input to pass through these areas and also prevents 
direct contact between the mosquitoes and the odour sources. During a test, odours in the air migrate down 
the branches, through the base leg and then to the holding port, from which test mosquitoes are released at 
the start of the test  
4.2.2.4  The time of day and assay conditions (i.e. temperature and humidity) should be recorded, and an 
attempt should be made to maintain these conditions in all subsequent tests in a single eva luation.  
4.2.2.5  A preliminary test with diluent only at one port of the test unit should be performed, with a 
sufficient number of replications to e nsure no response to the solvent (indicated by an attraction response ≤ 
10%).  DUS  2373 -2:2022 
© UNBS 202 2 – All rights reserved  7 
  
 
Figure 3 – Schematic drawing of a Y -tube olfactometer used to measure attraction –inhibition from the ability of 
a chemical to inhibit attraction to a port containing odours fr om a host . 
4.2.2.6  Two negative control assays are performed: one with no diluents (blank control) before active 
ingredient testing to ensure no contamination (indicated by ≤ 10% attraction to either port) and a second in 
which host odour is released from  both ports (positive control) to ensure no contamination by attraction –
inhibitor from a previous test (indicated by equal responses to both ports and > 50% response overall).  
4.2.2.7  Serial dilutions of active ingredient are made with methanol (or anothe r suitable diluent based on 
active ingredient chemistry and the manufacturer’s recommendation) and tested to identify the effective dose 
range. Dosages that give responses between 10% and 95% are used for this analysis, preferably with two or 
three dosages  that induce an attraction response of > 50% and the remaining two or three dosages that 
induce an attraction of < 50%.  
4.2.2.8  A pipette is used to deliver 400 μl of the repellent active ingredient active ingredient solution or 
diluent to a 9 -mm vial cap . All vial caps, both control (diluents only) and treatment (active ingredient and 
diluent), are placed in position in the end caps and attached to the trapping ports before a test. The placement 
of spatial repellent and control treatments should be fully randomized in replicates.  
4.2.2.9  The olfactometer is operated with airflow in a chemical hood. Hoods are equipped with vacuum 
and air lines that can be used to provide this airflow. The vacuum line in a hood can be connected to the base 
leg trap by an en d cap fitted with a gas nozzle. An anemometer is used to adjust the vacuum so that the 
airflow through the control and treatment ports is 0.20 ± 0.05 m/s. The air velocity through the base leg should 
be 0.40 ± 0.10 m/s.  
4.2.2.10  Lots of 10 female mosquito es are introduced from holding tubes into the holding port (with 
aspirators) and are allowed to acclimatize to the test environment with clean air for 15 min with no treatment. 
The numbers of mosquitoes that are physically damaged and are incapable of flyi ng or walking are 
discounted; only those mosquitoes that are able to respond are observed and recorded for each replicate. 
After the acclimatization period, the treatment and control are positioned in corresponding ports, and the doors 
are opened for the e xposure period, usually 30 s. The exposure period is species specific and is determined 
by the measurement in the negative control assay of the initial attraction response (i.e. 50% total movement). 
The total numbers of  mosquitoes in the treatment trapping  port, the control trapping port and outside these 
trapping ports are recorded.  
4.2.2.11  Between replicates, the end caps and trapping ports are disconnected from the branches of the 
Y-tube, and the end cap and holding port are disconnected from the base leg. Clean holding and trapping 
ports are then placed on the unit, with the end caps reinstalled, and the unit is passively cleaned (with airflow) 
for a minimum of 3 min under the chemical hood to allow odours from the active ingredient and/or host to clea r 
from the olfactometer before the next replicate.   
8 © UNBS 202 2 – All rights  reserved  
 4.2.2.12  During the ventilation period, all traps remain in place. Successive replicates are done by 
repeating the process of loading a new trap with 10 mosquitoes onto the base leg and allowing the 
mosqu itoes to acclimatize.  
4.2.2.13  The Y -tube body and individual trapping ports are washed at the end of each chemical 
evaluation. As the unit is made of acrylic, all parts should be washed with non -fragrant laboratory detergent 
solution. Component sections are allowed to dry overnight before reuse for testing other active ingredient 
and/or dosages.  
4.2.2.14 A minimum of six replicates is performed for each active ingredient dosage. At the end of testing, 
the proportion of mosquitoes attracted to the treatmen t is determined. The percentage attracted to the 
treatment port is calculated by dividing the number of mosquitoes trapped in the treatment port by the total 
number of mosquitoes in the test (minus damaged mosquitoes). Spatial repellency is indicated by a lower 
percentage attraction of mosquitoes to host odours plus active ingredient than to host odours with diluent only 
(i.e. no active ingredient ). The mean percentage attraction is calculated from the responses of the six 
replicates to each treatment.  
4.2.2.15  The percentage attraction for each AI dosage is determined by probit -plane regression analysis, 
from which the ED 50 and ED 95 and corresponding 95% confidence limits can be estimated. The number of 
replicates, the total number of mosquitoes and the me an percentage attraction (± standard error) for each 
active ingredient dosage and negative control should be reported.  
4.3  Spatial repellency of active ingredients against insecticide -resistant strains  
The objective of this study is to determine any diffe rence in spatial repellency between susceptible and 
insecticide -resistant strains to provide information for disease protection and control strategies. The difference 
is determined by comparing the dose –response curves generated in the spatial repellency a ssay and the 
olfactometer assay, as outlined above (sections  4.2.1 and  4.2.2) against mosquito populations that are known 
to be resistant.  
4.4  Protective efficacy of formulated products  
4.4.1 The objective of this study is to determine the optimum dosage( s) to be applied (Note 1) and the 
duration of protective efficacy in a specified treated space under well -controlled and standardized conditions. 
Protective efficacy (personal protection) is measured by the difference in the inhibition of landing or feedin g 
between treated groups and controls over time. The reduction in vector entry into or resting inside test spaces 
can be compared (Note 2) when appropriate.  
Note 1   The necessity for testing various dosages of a formulated product depends on whether a fina l product or a 
product that is formulated but still under development is being evaluated.  
Note 2  A decision to include measures of reduced entry and resting in addition to or in place of landing or feeding 
inhibition for estimating protection time should be based on product claims. If a claim states that the product prevents 
insects from entering a space, entry evaluation is necessary.  
4.4.2  Products should be evaluated and placed in the free -flight room according to the label instructions. 
The efficacy o f a product is assessed from a minimum of four replicates with 50 mosquitoes for both treatment 
and control. Comparison with a standard product or suitable positive control is necessary. The duration of 
protective efficacy over time can be measured by maki ng collections at various times after product activation 
from laboratory findings and/or label claims. For example, if the product performance in laboratory testing 
indicated 18 -week efficacy, tests should be performed at systematic sampling times (e.g. we ekly) throughout 
the 18 -week expected efficacy period. Products should be stored according to the label claims between 
evaluations under environmental conditions similar to those during evaluation. Longer -lasting products can be 
stressed or aged experiment ally in environmental chambers before testing.  
4.4.3  Free-flight rooms constructed within testing facilities should be mosquito -proof and well ventilated, 
with an extraction fan for safety to clear vapour remaining from spatial repellent formulations betw een tests. 
Rooms should measure 30 m3,(Note 3) with smooth, light coloured surfaces such as tiles (walls, ceilings and 
floors) that make it easy to see mosquitoes and easy to clean with detergent or solvent. Before evaluation of DUS  2373 -2:2022 
© UNBS 202 2 – All rights reserved  9 
 repellents, the chambers sh ould be cleaned with suitable detergent or solvent and ventilated to clear residual 
traces of cleaning product. Rooms should be maintained at 27 ± 2 °C and 80% ± 10% relative humidity during 
the test period and evaluations conducted at appropriate times in  the diel period for the target mosquito 
species. Instrumentation should be mounted in the room to ensure consistent comparison of measurements 
over time.  
Note 3   This minimum volume space was set on the basis of the WHO Guidelines for efficacy testing of household 
insecticides products, Geneva, 2009.  
4.4.4  A domestic extractor fan or passive ventilator is switched on (air exchange of about 110 m3/h), and a 
single person remains in the room for the duration of the tests, either to conduct a human landing c atch for 
measuring landing inhibition or to measure feeding inhibition. The placement of the product in the free -flight 
room should be in accordance with the label instructions. The duration of the evaluation and sampling periods 
depends on the product lab el specifications. Biological efficacy should be assessed at several times, until it 
has fallen to < 50%.  
4.4.5  Mosquitoes should be allowed to acclimatize for 1 h under conditions similar to those of the test 
space before they are released into the test area. Mosquitoes are released into the room containing a human 
volunteer or an adjacent room if vector entry into a space is the objective of the evaluation. If human landing 
catch is being measured, mosquitoes are collected for 1 h continuously. If feedin g inhibition is being 
measured, the volunteer remains in the room for the period of interest, and blood -fed mosquitoes are collected 
by aspiration from the interior space at the end of the test.  
% landing inhibition =           
     
  
Where,  
Cl  is the num ber of mosquitoes landing in the control space, and  
Tl  is the number of mosquitoes landing in the treatment space.  
 
Where,  
Cf  is the number of blood fed mosquitoes in the control space, and  
Tf  is the number of blood fed mosquitoes in the treatment spac e. 
4.4.6  An appropriate statistical analysis (e.g. probit -plane regression or linear mixed -effects regression 
with an appropriate error structure and link function) at a significance level of p = 0.05 should be used. Data 
should include the duration of th e test, the duration of protective efficacy, the number of replicates of the 
control and treatment and the mean percentage landing inhibition or feeding inhibition with the 95% 
confidence interval. The size of the room(s) used in the evaluation should be r eported in m3. If more than one 
interconnected room is used, the distance between the source of the spatial repellent and the human should 
be stated.  
Note 4   Usually, the effective dose that provided 99.9% protection in a defined time in laboratory testing  is used to 
establish the dosages for semi -field trials.   
10 © UNBS 202 2 – All rights  reserved  
 5  Semi -field trials of formulated products  
5.1  General  
5.1.1 The objective of semi -field trials is to extend the results of laboratory efficacy studies and to test 
formulated products against free -flying populations of one or more target species under simulated indoor or 
outdoor conditions.  
The specific objectives of these trials are to determine the optimum application dosage(s) (Note 5) and 
duration of protective efficacy in a specific treated ind oor space or outdoor area. Efficacy (personal protection) 
is measured by comparing landing inhibition or feeding inhibition in treatment and controls over time. 
Alternatively, a reduction in vector entry into or resting in the test space may be compared. ( Note 6).  
Note 5   The necessity for testing various dosages of a formulated product depends on whether a final product or a 
product that is formulated but still under development is being evaluated.  
Note 6   A decision to include measures of reduced entry an d resting in addition to or in place of landing or feeding 
inhibition for estimating protection time should be based on product claims. If a claim states that the product prevents 
insects from entering a space, entry evaluation is necessary.  
5.1.2  Semi -field trials are conducted in screened enclosures (with or without experimental huts) using the 
release of well characterized mosquitoes, ideally in the natural ecosystem of a target disease vector. The 
advantages of using screened enclosures for semi -field evaluation ensures that the mosquitoes are pathogen -
free, that a known number of mosquitoes of fixed physiological status (e.g. parity) is used and there is a 
known distance between the point at which the mosquito populations originate and the source of th e chemical 
stimulus, allowing estimation of the protective area (especially important in outdoor evaluation).  
5.1.3  Appropriate arthropod containment guidelines should be followed. The use of netting around the 
enclosure allows tests to be conducted in lo cal conditions at ambient temperature, light, humidity and air 
movement. The enclosure should be sufficiently large to reflect the area over which the product is intended for 
use. 
5.1.4  The dimensions of screened enclosures should be reported in m3, with a minimum size of 10 x 10 x 2 
m2 per compartment and, ideally, three identical compartments to evaluate simultaneously: the spatial 
repellent, a negative control and a positive control. It is important to evaluate each treatment independently of 
the others  and to avoid interaction between treatments, especially as spatial repellents may exert an 
effectover several metres. Testing a spatial repellent and a control in the same space can result in a push –pull 
effect, resulting in over estimation of the repelle nt’s efficacy.  
5.1.5 To facilitate sampling, it is preferable to conduct evaluations in enclosures with cement floors 
surrounded by a water -filled moat to prevent entry of ants, so that resting or blood -fed mosquitoes are not 
scavenged by them. Evaluations  should be conducted at appropriate times in the diel period for the target 
mosquito species. Temperature, humidity and airflow should be recorded throughout the test. Instrumentation 
should be mounted in each compartment in the same location to allow cons istent comparisons of 
measurements.  
5.2  Study design  
5.2.1  A minimum of three semi -field trials in three geographical setting is recommended. Human landing 
catches are performed during the natural diel pattern of the target species. For target species th at have a 
short period of main biting activity, tests with spatial repellent material should be conducted such that the 
expected end -points occur within the biting period.  
5.2.2 The duration of protective efficacy (inhibition of landing and feeding) can be  measured by collecting 
mosquitoes at various times after product activation as shown in laboratory findings and/or label claims. For 
example, if a product is claimed from laboratory testing to be effective for 18 weeks, field trials should be 
performed at  systematic sampling times (e.g. weekly) throughout the 18 -week expected efficacy period.  DUS  2373 -2:2022 
© UNBS 202 2 – All rights reserved  11 
 5.2.3  Products should be stored between evaluations according to the label claims under environmental 
conditions similar to those during evaluation. Longer -lasting p roducts can be stressed or aged experimentally 
in environmental chambers to facilitate logistics.  
5.2.4  The dosage(s) for evaluation of spatial repellent products should be based on laboratory studies  (see 
section 4 .2.1).  
5.2.5  The number of replicates p er product being evaluated should be based on sample size estimates, 
which are required to ensure that a statistical evaluation has sufficient power and depend on the expected 
efficacy of the repellent. It is highly desirable that all field operatives be ‘ blinded’ regarding the allocation of 
treatments to avoid bias during the evaluation. If that is not possible owing to the characteristics of the product 
(e.g. odour), the data should be coded by an independent person before analysis.  
5.2.6  For each evalua tion, a randomized Latin square design is used. The number of volunteers is equal to 
the number of products to be tested plus both positive (standard product if available) and negative (no 
product) control(s). Negative controls are used to monitor mosquito  landing or feeding response, depending 
on the outcome of interest. If overall landing or biting in the controls is < 50% or < 25%, respectively, the data 
should be discarded and another replicate performed.  
5.2.7  Collections are performed by volunteers s killed in the use of aspirators, so that they catch all 
mosquitoes landing on an exposed limb (for landing inhibition) or all those that are blood -engorged and resting 
(for biting inhibition). Records should be made throughout each trial of wind speed and direction, temperature, 
relative humidity and precipitation for consideration and analysis if appropriate.  
5.3  Indoor effective dosage and duration of protective efficacy  
5.3.1  Indoor trials can be performed in experimental huts within a screened enclosu re. Ideally, several huts 
should be available to allow comparison of several treatments simultaneously. In order to estimate efficacy in 
local houses, the experimental huts at the test site should be similar in design (e.g. number, orientation and 
size of windows and doors), volume (a minimum of 30 m3, unless local homes are much smaller) and 
materials and be constructed in the fashion of indigenous homes at the site with locally acquired materials 
when possible. Although hut designs may vary by test site, depending on local culture, it is critical that the 
design used at a specific evaluation site is standardized to allow direct comparison of AIs or formulated 
products.  
5.3.2  An appropriate description of the design, size, furnishings, wall and ceiling cha racteristics and layout 
should be reported. Huts should be checked for contamination by an appropriate control test before evaluation 
of each new product. The attractiveness of the experimental huts to the target species should be tested before 
the trial u sing landing rates under control conditions.  
5.3.3  The study design for indoor evaluation of point -source treatments (e.g. coils and emanators) differs 
from that for nonpoint source treatments (e.g. treated textiles or wall surfaces). Point -source treatme nts can 
be rotated between huts, whereas rotation of non -point source treatments may be limited by format. For point -
source trials, rotation between huts should be in accordance with a Latin square design, in which every 
treatment is tested in every hut an  equal number of times.  
5.3.4  Rotation schedules should be based on the expected protection time from laboratory findings or 
product claims, with 1 or 2 days between rotations to clean and ventilate the hut and to remove contamination 
from previous treatm ents. When non -point source products cannot be rotated, it is essential to demonstrate 
before the evaluation that the attractiveness of experimental huts has little or no variation. (This also shows 
the importance of optimum positioning during selection or  construction.)  
5.3.5  Human volunteers are positioned at the centre of each hut throughout a single test to either conduct 
a human landing catch for measuring landing inhibition or to rest or sleep for measurement of feeding 
inhibition. Product placement in the hut should be in accordance with the label instructions. The duration of the 
evaluation and sampling periods will depend on the product label specifications.  
5.3.6  Each replicate consists of releasing 100 mosquitoes inside the hut, for both the tre atment and 
negative control. A positive control can be used when appropriate. The mosquitoes collected are placed in  
12 © UNBS 202 2 – All rights  reserved  
 separate holding cups for each sampling period. If insecticidal activity is indicated in laboratory studies, knock -
down must also be monito red inside huts. All mosquitoes are held 24 h at optimum temperature and humidity 
conditions for observation of mortality. Data should be reported for knockdown, mortality, blood -fed status and 
location of collection (to estimate movement into or out of th e test structure).  
5.3.7  Marking each release population with a different coloured fluorescent powder can facilitate recapture; 
however, the effect of marking on mosquito behavior and mortality should be evaluated before use in testing. 
Mechanical aspirat ion can be used to recapture all mosquitoes that were not collected during testing and 
remain inside the screened enclosure.  
5.3.8  At the end of a trial, the number of mosquitoes collected during each observation period (i.e. at hour 
1, hour 2 and hour 3)  in the treatment and control groups can be averaged for each replicate (i.e. full 
treatment rotation). Landing inhibition or feeding inhibition is reported as a percentage with a 95% confidence 
interval (see section 4.3). An appropriate statistical analys is (e.g. probit -plane regression or linear mixed -
effects regression with an appropriate error structure and link function) at a significance level of p = 0.05 
should be used for comparison.  
5.3.9  The data reported should include the duration of the test, the age of the product (duration of protective 
efficacy), the number of replicates of the control and treatment, mean percentage landing inhibition or mean 
percentage feeding inhibition with 95% confidence interval.  
5.4  Outdoor effective dosage and durati on of protective efficacy  
5.4.1  In a semi -field system, volunteers are positioned singly at a collection station at a specified distance 
from the spatial repellent product, according to the label recommendations, or act as a control for the duration 
of the test to either conduct human landing catch for measurement of landing inhibition or to rest or sleep for 
measurement of feeding inhibition. The duration of the evaluation and sampling periods depends on the 
product label specifications.  
5.4.2  Two semi -field compartments are used simultaneously to monitor landing inhibition at a set distance 
from a spatial repellent or control.  
5.4.5  Each replicate consists of releasing 100 mosquitoes, for both the treatment and the negative control. 
Mosquitoes are relea sed from netted boxes at a set distance from the volunteer by a pulley system. Plastic 
sheeting is used to separate semi -field compartments to ensure the independence of samples. Control and 
treatment can be rotated by day to prevent interference among col lection stations. Temperature, humidity, 
wind speed and direction should be recorded for the duration of each replicate. For each defined distance, 
evaluations should be repeated.  
5.4.6  At the end of a trial, the number of mosquitoes collected within each  observation period (e.g. at hour 
1, hour 2 and hour 3), for treatment and control, can be averaged for each replicate (i.e. full treatment 
rotation). The data reported should include the duration of the test, the age of the product (duration of 
protective  efficacy), the number of replicates of the control and treatment, the mean percentage landing 
inhibition or mean percentage feeding inhibition (Equation 3) with 95% confidence interval (see section 4.3). 
The size of the semi -field system used during the e valuation should be reported in m3. Efficacy at each 
distance between the source of the spatial repellent and the volunteer should be stated. An appropriate 
statistical analysis (e.g. probit -plane regression or linear mixed effects regression with an appro priate error 
structure and link function) at a significance level of p = 0.05 should be used for comparison.  
6  Field trials of formulated products  
6.1  The objectives of field trials are to measure the personal protection offered by a spatial repellent 
product in operational settings and against free -flying natural indoor and/or outdoor populations of a target 
species. These are measured by comparing landing inhibition with treatment and with control. (Note 7)  
Note 7   Because of ethical considerations, alt ernative collection methods and measures might be required to assess 
personal protection in locations with known active circulation of arboviruses (i.e. dengue), such as monitoring indoor 
resting density, use of outdoor traps or monitoring mosquito entry w ith window traps.  DUS  2373 -2:2022 
© UNBS 202 2 – All rights reserved  13 
 6.2  The specific objectives of such tests are to:  
a)  confirm the effective dosage under operational conditions;  
b)  observe and record the ease of application, handling and perceived adverse -effects during product 
application and use; a nd 
c)  observe and record community acceptance.  
6.3  Operational trials may have to be conducted in different ecological settings (e.g. urban or rural and 
indoor or outdoor), depending on the target species. The area and location of trial sites should be 
representative of the target species’ habitat and the expected conditions of human exposure. Trials should be 
sufficiently replicated to allow robust statistical analysis with relevant sample size estimations based on 
predicted product efficacy. The outcome s are locale -specific, and the results may not be applicable to other 
settings. The environmental conditions of temperature, humidity and wind speed should be reported during 
both indoor and outdoor evaluations. Information on the insecticide resistance pr ofile of the target species is 
desirable.  
6.4  For indoor evaluations, several houses should be used, when feasible. Houses should be well 
described, especially with regard to the conditions relevant to product efficacy, including estimates of indoor 
volum e and air ventilation (e.g. sealed or gapped walls, number of windows, doors or eave area). Houses are 
randomized to receive either active (formulated spatial repellent) or blank (placebo; inert ingredients alone) 
treatment during the trial. Collectors sho uld be ‘blinded’ to treatment allocation.  
6.5  In outdoor evaluations, spatial repellent product or blank should be allocated randomly to comparable 
outdoor spaces with human exposure.  
6.6  A minimum of three replicates is required on different occasions a t the optimal dose required for a 90% 
reduction in landing inhibition or a statistically significant difference between treatment and control at the 
dosage recommended on the label. The initial dosage for operational trials should be based on the dosage(s)  
recommended on the label or that which inhibited feeding by at least 90% in semi -field trials. The number and 
placement of spatial repellent products should be based on label claims.  
6.7  Human landing catch methods should be used to measure protective ef ficacy. The method, statistics 
and minimum data reporting for evaluation of landing inhibition are outlined in sections 5.3 and 5.4 for indoor 
and outdoor trials, respectively.  
6.8  It is advisable that the health status of volunteers be examined before, d uring and after product use. 
Brief records of exposure should be kept for each volunteer, including the spatial repellent product used, the 
dosage, total exposure in hours and any perceived adverse -effects. A list of mild, moderate and severe signs 
and sym ptoms of poisoning can be kept for reference. Problems encountered in use and application should be 
reported. The material safety data sheet issued by the manufacturer should be consulted if necessary.  
6.9  Perceived adverse -effects (and other adverse even ts) due to use of the spatial repellent product 
indoors or outdoors and the general acceptability of treatment by local inhabitants in the trial area should also 
be observed and recorded.  
7  Ethical considerations  
7.1  General  
7.1.1  Participants’ well -being must be assured and their autonomy respected. The inclusion and exclusion 
criteria for participation in a test, informed consent for risk of pathogen infection, pathogen detection and 
monitoring as well as chemoprophylaxis and treatment should follow na tional guidelines, and the study 
protocol should be approved by the relevant research ethics committee in the country or institution in which 
the study is taking place.   
14 © UNBS 202 2 – All rights  reserved  
 7.1.2  Like all studies in which infectious agents are involved, efficacy testing often  entails an occupational 
risk of acquiring infection in both laboratory and field settings. Measures for reducing such risks have been 
developed and widely implemented and include insect containment and manipulation, worker training and 
using known uninfec ted target species, when possible.  
7.1.3  When human participants are hired or recruited, they must be informed about any responsibilities that 
may expose them to vectors, such as colony maintenance or conducting human landing catches in natural or 
field c onditions. Participants are then expected to follow standard protocols, as outlined by the project leader 
or national guidelines; they will therefore be protected under occupational health standards to control 
exposure to biohazards.  
7.2  Informed consent  
Volunteers should be given the full details of the project, including the purpose of the study, the procedures, 
product to be evaluated, the risks and benefits, reporting adverse effects and the voluntary right to refuse or 
withdraw from the study. Informe d consent is usually documented on a signed and dated consent form. An 
example of an informed consent document is provided in Annex B.  
7.3  Human landing catch in semi -field and field testing  
7.3.1  Evaluations of landing and feeding inhibition should be b ased on the pathogen -specific risks of 
volunteers. By using laboratory -reared mosquito populations in semi -field trials, however, it may be acceptable 
to allow mosquitoes to feed with minimal or no greater risk of disease for the volunteers.  
7.3.2  In all instances, ethical clearance from relevant ethics committees and informed consent from 
participating individuals is mandatory. In malaria -endemic countries, all participants must be screened for 
malaria before participation, and only parasite free individu als should be allowed to participate.  
7.3.3  For field trials with human landing catch in areas endemic for vector -borne disease, it is 
recommended, when feasible, to use healthy male recruits aged between 18 and 45 years. Males from 
outside the trial area  (with potential exposure to unmatched vectors) and pregnant women should be 
excluded.  
7.3.4  Volunteers should be given protective clothing (i.e. a screen mesh jacket to protect the upper body, 
head and face, and closed -toe shoes to prevent bites to the f eet). In malaria endemic countries, it is 
recommended that participants in field trials be given appropriate prophylaxis, when possible under 
supervision to ensure correct compliance.  
7.3.5  When applicable, participants should be screened for parasitaemia  by WHO standard microscopy or 
a parasite -appropriate rapid diagnostic test; malaria treatment should be provided subsequently for infected 
volunteers, according to national ethical guidelines.  
7.3.6  Alternative methods for assessing personal protection m ay be required in field trials conducted in 
locales with known active circulation of arboviruses (i.e. dengue), such as monitoring indoor resting density, 
use of outdoor traps or monitoring mosquito entry with window traps.  DUS  2373 -2:2022 
© UNBS 202 2 – All rights reserved  15 
 Annex A  
(Informative )  
 
Definit ion of knockdown and mortality for adult mosquitoes  
For the purpose of insecticide bioassays, the definition of knock -down and mortality involves not only the state 
of the insect but also the time at which the observation is made.  
A mosquito is classified as dead or knocked down if it is immobile or unable to stand or take off (Table A1). 
The distinction between knocked down and dead is defined only by the time of observation. The assessment 
of knock -down is made within 60 min post -exposure. Mortality is de termined at least 24 h post -exposure. The 
holding container may be tapped a few times before a final determination is made.  
In the case of slow -acting insecticides, the recovery period may be extended beyond 24 h. Control mortality 
should be measured over the same recovery period. Mortality after 24 h should be recorded and, in some 
cases, repeated observations may be appropriate.  
Table A1 – Classification of adult mosquitoes as alive, knocked down or dead in bioassays  
Alive  Knocked down after 60 minutes or  dead after 24 hours of exposure  
Moribund  Dead  
Can both stand on and fly in a 
coordinated manner   Any mosquito that cannot 
stand (e.g. has 1 or 2 legs)  
 Any mosquito that cannot fly 
in a coordinated manner  
 A mosquito that lies on its 
back, moving legs and  wings 
but unable to take off  
 A mosquito that can stand 
and take off briefly but falls 
down immediately  No sign of life; immobile; cannot stand  
  
16 © UNBS 202 2 – All rights  reserved  
 Annex B  
(Informative )  
 
Example of informed consent form  
B.1 Informed consent form for participants in human  landing catches for : (name the 
group of individuals for whom this consent is written)  
Insert project title …………………………………………………………………… ………………….  
Name of principal investigator …………………………………………………………………………  
Name of organization ……………………………………………………………………………………  
Name of sponsor ………………………………………………………………………………………….  
Name of proposal and versio n ………………………………………………………………………….  
This informed consent form has two parts:  
 Information sheet (to share information about the research with you)  
 Certificate of consent (for signa ture it you agree to take part)  
You will be given a copy of the full informed consent form.  
Date and signature…………………………………………  
 B.2 Part I: Information sheet  
This sheet is a suggestion or example that can be modified according to the national rules and gui delines.  
B.2.1 Introduction  
Briefly state who you are, and explain that you are inviting them to participate in the research you are doing. 
Inform them that they may talk to anyone they like about the research and that they can take time to reflect on 
whet her they want to participate. Assure the person that if he or she does not understand some of the words 
or concepts, you will take time to explain them as you go along and that they can ask questions now or later.  
(Example: I am …………………., working for the … ………………….. <name of the research institute>. We are 
doing research on …………………….. disease, which is very common in this country. I am going to give you 
information and invite you to be part of this research. You do not have to decide today whether you will 
participate in the research. Before you decide, you can talk to anyone you like about the research. There may 
be some words that you do not understand. Please ask me to stop as we go through the information, and I will 
taketime to explain. If you have quest ions later, you can ask [name of responsible staff]).  
 DUS  2373 -2:2022 
© UNBS 202 2 – All rights reserved  17 
 B.2.2 Purpose of the research  
Explain in lay terms why you are doing the research. The language used should clarify rather than confuse. 
Use local, simplified terms for a disease, e.g. local name inste ad of malaria, mosquito instead of anopheles, 
“mosquitoes help in spreading the disease” rather than “mosquitoes are the vectors”. Avoid using terms like 
‘pathogenesis’, ‘indicators’, ‘determinants’ and ‘equitable’. There are guides on the Internet to help  you find 
substitutes for words that are overly scientific or are professional jargon.  
(Example …………………disease is transmitted through the bites of ………………mosquitoes. Knowledge of 
mosquito behaviour and how new methods to keep mosquitoes away from humans wil l help improve mosquito 
control in the area. In this study, we are testing a new repellent that will keep mosquitoes from biting humans. 
Studies in laboratories have shown this repellent is …………effective, and we want to check this result with 
mosquitoes in  this area to make sure it is useful for people to use here.)  
B.2.3 Type of research intervention and procedures  
State briefly the type of intervention that will be undertaken.  
 As a participant you will be asked to collect mosquitoes landing on you before they bite you between 
….. : ….. and ….. :…… h. This involves collecting mosquitoes that land on your legs with a tube and a 
torch.  
 You will be asked to not smoke cigarettes or drink alcohol for the days or weeks that you are 
participating.  
 We will provide you with …………………………………………………… medicine to stop you getting 
malaria if a mosquito with malaria does manage to bite you. You will have to take this every week and 
sign a form to show that you have taken the medicine; it will be paid for by the study.  
 You wil l have to take a malaria test every week that you are working on the study and sign a form to 
show that you have taken the test; it will be paid for by the study. If you are sick we will not be allowed 
to continue in the study.  
 You can leave the study at a ny time without explanation. It is your choice to take part.  
B.2.3.1  Example of question to improve understanding:  
B.2.3.1 .1 Do you know why we are asking you to take part in this study?  
B.2.3.1 .2 Do you know what the study is about?  
B.2.4 Voluntary part icipation  
Indicate clearly that the person can choose to participate or not. This can be repeated and expanded upon 
later in the form as well, but it is important to state clearly at the beginning of the form that participation is 
voluntary so that the oth er information can be heard in this context.  
(Example: Your participation in this research is entirely voluntary. It is your choice whether to participate or 
not. You may change your mind later and stop participating even if you agreed earlier.)  
B.2.4.1  Examples of question to improve understanding:  
B.2.4.1.1  If you decide not to take part in this research study, do you know what your options are?  
B.2.4.1. 2 Do you know that you do not have to take part in this research study, if you do not wish to? Do 
you have any questions?   
18 © UNBS 202 2 – All rights  reserved  
 B.2.5  Risks  
Explain and describe any possible or anticipated risks. Describe the level of care that will be available in the 
event that harm does occur, who will provide it, and who will pay for it. A risk can be thought of as being th e 
possibility that harm may occur. Provide enough information about the risks to allow the participant to make an 
informed decision.  
B.2.5.1  Example  
The risk of this study is you may be made uncomfortable by mosquito bites, and you have a small risk of 
getting ……………… disease, even though you are taking …………. medicine to prevent it. You will be given 
protective clothing to make sure mosquitoes can bite only on your legs, where you can catch them before they 
have time to bite. If you do become ill at any time  during the study or during 1 month after the study, you will 
receive the correct treatment from…………………………… hospital. All costs will be paid by the study. There 
is also a risk that you might have some side effects from taking medicines to stop getting ………… …… 
disease. If you feel unwell, you will see a doctor at …………………………… hospital who will give you the 
correct care and change the medicines you are taking.)  
B.2.5.1 .1 Examples of question to improve understanding:  
B.2.5.1.1 .1 Do you understand that, while t he research study is under way, you will receive free health 
care from …………………………… hospital?  
B.2.5.1. 1.2 Do you understand that you may have some unwanted side -effects from the medicine to stop 
getting ……………… disease? Do you have any other questions?  
B.2.6 Benefits  
Mention only those activities that will be actual benefits and not those to which the prospective participants are 
entitled regardless of participation. Benefits can be categorized as those to the individual, those to the 
community in which the individual resides and those to society as a whole as a result of finding an answer to 
the research question.  
B.2.6.1  Example  
 If you participate in this research, you will have the following benefits: you will be paid 
..................................... ... for your work each night for up to .............................. nights and will have a taxi 
home or accommodation at night after you have finished work.)  
B.2.6.2  Examples of que stion to improve understanding  
B.2.6.2.1  Can you tell me if you have unde rstood correctly the benefits that you will have if you take part in 
the study?  
B.2.6.2.2  Do you know if the study will pay for your travel costs and time lost, and do you know how much 
you will be reimbursed? Do you have any other questions?  
B.2.7 Right to refuse or withdraw  
This is reconfirmation that participation is voluntary and includes the right to withdraw.  
B.2.7 .1 Example  
You do not have to take part in this research if you do not wish to do so. You may also stop participating in the 
research at a ny time you choose. It is your choice and all of your  rights will still be respected.  DUS  2373 -2:2022 
© UNBS 202 2 – All rights reserved  19 
 B.2.8  Who to contact  
Provide the name and contact information of someone who is involved, informed and accessible (a local 
person who can actually be contacted). State th at the proposal has been approved and how.  
B.2.8.1 Example  
If you have any questions you may ask them now or later, even after the study has started. If you wish to ask 
questions later, you may contact any of the following: [name, address/telephone number/ e-mail]).  
This proposal has been reviewed and approved by [name of the local ethical review board], which is a 
committee that makes sure that research participants are protected from harm. If you wish to find 
more about the ethical review board, contact [n ame, address, and telephone number.]).  
B.2.8 .2 Example of question to improve understanding  
B.2.8 .2.1 Do you know that you do not have to take part in this study if you do not wish to?  
B.2.8 .2.2 Do you know that you can say ‘No’ if you wish to?  
B.2.8 .2.3 Do you know that you can ask me questions later, if you wish to?  
B.2.8 .2.4 Do you know that I have given the contact details of the person who can give you more 
information about the study?  
B.2.8 .2.5 You can ask me any questions about any part of the res earch study, if you wish to. Do you have 
any questions?  
B.3 Part II: Certificate of consent  
This section should be written in the first person and contain a statement similar to the one in bold below. If 
the participant is illiterate but gives oral consent , a witness must sign. A researcher or the person going over 
the informed consent forms must sign each form .  
The certificate of consent should avoid phrases starting with “I understand….”. Understanding is 
better tested by targeted questions during the re ading of the information sheet (Some examples of 
questions are given above) or by questions asked at the end of the reading of the information sheet, if 
the potential participant is reading the information sheet him - or herself . 
B.3.1  Example  
I, ………………………… ……………………., have clearly been informed of the aims of the project entitled 
“……………………” and I agree to participate in the study. During my participation in these studies, I have 
been told that mosquitoes can bite me and they may be carrying parasites. I am fu lly aware that I may revoke 
my consent and leave the study at any stage . 
Print name of participant: …………………………………………………………………………………………  
Signature of participant: …………………………………………………………………………………………  
Date: …………/………………/………………. .. 
Witness name: ……………………………………………… ……………………………………………….  
Witness signature: ……………………………………………………………………………………………  
Dates: …………………………………………………………………………………………………………….   
20 © UNBS 202 2 – All rights  reserved  
 If illiterate  
A literate witness must sign (if possible, this person should be selected by the participant and should have no 
connection to the research team). Participants who are illiterate should oppose their thumb print as well.  
B.3.1.2  Example  
I have witnessed the accurate reading of the consent form to the potential participant, and the individual has 
had the opportunity to as k questions. I confirm that the individual has given consent freely  
Print name of participant: … …………………………………………… and Thumb print of participant  
Signature of witness: ………………………………………………………………………………………………  
Date: …………/………………/………………..  
B.3.2  Statement by the re searcher or other person taking consent:  
I have accurately read out the information sheet to the potential participant and to the best of my ability made 
sure that the participant understands that the following will be done:  
1. Human landing catch will be conducted between..... . :..... and..... :...... hours  
2. The participant has been requested to refrain from smoking and consuming alcohol for the study duration.  
3. The participant will be given free malaria prophylaxis, screening and treatment for the dur ation of the study.  
4. The participant will be reimbursed …………………………… … for the working time taken up by the study.  
I confirm that the participant was given an opportunity to ask questions about the study, and all the questions 
asked by the participant were  answered correctly and to the best of my ability. I confirm that the individual has 
not been coerced into giving consent, and the consent has been given freely and voluntarily.  
A copy of this informed consent form has been given to the participant.  
Print name of researcher or other person taking the consent: ………………………………………………………..  
Signature of researcher or other person taking the consent: …………………………………………………………  
Date: ………………………………………………  
 DUS  2373 -2:2022 
© UNBS 202 2 – All rights reserved  21 
 Bibliography  
[1] RS 394 -2: 2018, Mosquito repellents — Performance t ests guidelines — Part 2: Spatial repellents  
  DUS 2373 -2:2022 
© UNBS 2022 – All rights reserved  23 
 Certification marking  
Products that conform to Uganda standards may be marked with Uganda National Bureau of Standards 
(UNBS) Certification Mark shown in the figure below.  
The use of the UNBS Certification M ark is governed by the Standards Act, and the Regulations made 
thereunder. This mark can be used only by those licensed under the certification mark scheme operated by 
the Uganda National Bureau of Standards and in conjunction with the relevant Uganda Stan dard. The 
presence of this mark on a product or in relation to a product is an assurance that the goods comply with the 
requirements of that standard under a system of supervision, control and testing in accordance with the 
certification mark scheme of the  Uganda National Bureau of Standards. UNBS marked products are 
continually checked by UNBS for conformity to that standard.  
Further particulars of the terms and conditions of licensing may be obtained from the Director, Uganda 
National Bureau of Standar ds.  
 
 DUS 2373 -2: 202 2   
 
ICS 65.100.10  
Price based on  nn pages  
© UNBS 202 2– All rights reserved